Disk Activity Plot Not Working With SAS Drives

phillxnet · October 24, 2018, 6:41pm

@juchong Hello again and thanks for the report.

I think this is probably down to either:

The stats not actually surfacing in /proc/diskstats (as is the case with md devices) as that is where we grab them from.
We are not usefully resolving the correct by-id name for the device, ie the /proc/diskstats uses the temp canonical type names but internally Rockstor uses the boot safe by-id type names: but there can be multiple by-id type names and for speed we take a short cut for these stats that may be coming back to bite us in this case (if I remember correctly).

The following code is the nub/core of the retrieval and includes the potential by-id reference:

rockstor/rockstor-core/blob/master/src/rockstor/smart_manager/data_collector.py#L567-L587


      
              def on_getfilesize(self, sid, logfile):
                  def file_size(logfile):
          
                      file_size = path.getsize(self.build_log_path(logfile))
                      self.emit("logsize", {"key": "logManager:logsize", "data": file_size})
          
                  self.spawn(file_size, sid, logfile)
          
          
          class DisksWidgetNamespace(RockstorIO):
          
              switch = False
              byid_disk_map = {}
          
              def on_connect(self, sid, environ):
          
                  self.byid_disk_map = get_byid_name_map()
                  self.switch = True
                  self.spawn(self.send_top_disks, sid)
          
              def on_disconnect(self, sid):

with the byid_disk_map referencing the output of:

github.com

rockstor/rockstor-core/blob/master/src/rockstor/system/osi.py#L1622-L1637


      
          /dev/disk/by-id/<dev_byid> Possible states are:
          unknown - command not supported by disk
          active/idle - normal operation
          standby - low power mode, ie drive motor not active ie -y will do this
          sleeping - lowest power mode, completely shut down ie -Y will do this
          N.B. -C shouldn't spin up a drive in standby but has been reported to wake
          a drive from sleeping but we aren't going to invoke sleeping as pretty much
          any request will wake a fully sleeping drive.
          Drives in 'sleeping' mode typically require a hard or soft reset before
          becoming available for use, the kernel does this automatically however.
          :param dev_byid: disk name as stored in db / Disk model ie without path
          :return: single word sting of state as indicated by hdparm -C /dev/<disk>
          and if we encounter an error line in the output we return unknown.
          """
          # TODO: candidate for move to system/hdparm
          # if we use the -C -q switches then we have only one line of output:

To help discern which is the cause you could give us the output of:

cat /proc/diskstats

while there is confirmed activity on the problematic reporting devices (two consecutive readings would be nice as well) and also a screen shot of your disks page to see what by-id names Rockstor is using, so we can check for (2) above.

It will also be necessary to report the full output of the following command:

ls -la /dev/disk/by-id

Note that at least all of the above requested information will be required to pin this down. But if these drives are like the md case they just don’t report their activity in that way. But I’m guessing we have a (2) type cause on this one. Just a quick guess for the time being though until get more info.

Hope that helps and thanks again for the report.

I’m assuming your last report ended up resolving itself successfully in time as there was no further update after my subsequent reply in that thread?

Best to reply contextually there I would say on that one.